Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
Fiber networks can be used to transport light that is modulated to carry information and to deliver communication services in various configurations, including broadband fiber-to-the-premise (“FTTP”) communication services. In order to promote widespread deployment of FTTP broadband infrastructure, it is desirable to reduce the cost of fiber plant construction, which consists of as much as 80% of the total cost for FTTP deployments and is dominated by labour costs in developed countries. Techniques that can reduce this upfront expense associated with the initial fiber plant can further this goal. However, ongoing operation and maintenance expenses associated with the fiber plant also impact the adoption rate of FTTP communication services. One such expense is the detection and finding location of fiber faults (e.g., a fiber cut, disconnection or breakage) that interrupt communication services. Such detection is necessary for repairing the broken fiber link and restoring the communication services. Techniques that can quickly and efficiently detect and locate these faults reduce the operation and maintenance expenses and further encourage adoption of FTTP communication services. In addition, these techniques shorten service outage time and improve user experiences.
Existing and known architectures require manual use of optical time domain reflectometry (“OTDR”), wherein OTDR is a measurement technique used to quickly and efficiently diagnose a fiber plant and identify location of a fiber fault that brings down or otherwise degrades a transmission link. OTDR can be applied to a faulty fiber link to localize faults such as a fiber cut, a macro bend, etc. OTDR gives the optical distance of the fiber fault (called events) from the source where the OTDR test signal is launched. When combined with geographic information system (“GIS”) data regarding the physical routes of the fiber plant and knowledge of which customer has lost communication with the central office providing the communication services, OTDR can be leveraged to quickly and efficiently identify and map the fiber fault location. As such, an effective fault diagnosis strategy that leverages the advantages of OTDR can help reduce operating costs of an FTTP access network. However, existing OTDR based techniques require strong manual intervention every time a fault is reported, wherein a technician takes OTDR to the fiber location, identifies optical distance of the fault using the OTDR, and then maps the distance on the GIS map to determine the location, which due to difference in optical distance vs actual physical distance makes it difficult for the technician to locate/rectify the actual fault location/site.
Therefore, OTDR fault diagnosis starts with identifying fiber link associated with CP that has lost service. A loss of signal may be a complete loss of communication with the CO or an unacceptable degradation of the communication link. Once the fiber link is identified, an optical test signal is launched at the head end into the faulty fiber link and the head end of the link is monitored for reflections or a “reflection signature” which may be analyzed to identify the location of the fiber fault. Since a pt-2-pt access network requires a homerun fiber termination to each CP, a large number of fiber links are terminated in the CO. In fact, a CO in an urban or suburban neighbourhood can expect to terminate as many as 50,000 pt-2-pt fiber links extending to various CPs. Conventionally, a technician physically present at the CO is needed to identify and manually couple the OTDR unit to the faulty fiber link. To speed up fiber diagnosis for pt-2-pt access networks, an OTDR test system needs the capability to pre-connect each homerun access fiber with an OTDR unit or have the capability to automatically switch a shared ODTR unit to the right fiber link. Hardware has been designed to share single OTDR with multiple fibers. Brute-force methods include coupling a single OTDR per fiber link or a very large-port-count optical switch can be used to multiplex the OTDR unit across a large number of fiber links. However, such brute-force approaches are prohibitively expensive.
There is therefore a need in the art for an improved architecture, technique, and method for efficiently, accurately, and quickly detecting the precise fault location.
All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.